Barrett's Esophagus (BE) is a condition of the esophagus that is pre-cancerous, a precursor to cancer of the esophagus. The standard practice for diagnosing Barrett's Esophagus is using flexible endoscopy, often with the esophageal lumen insufflated with air. A normal esophagus is usually light pink in color, while the stomach appears slightly darker pink. Barrett's Esophagus usually manifests itself as regions of slightly darker pink color above the lower esophageal sphincter (LES) that separates the stomach from the esophagus. It is preferable to diagnose Barrett's Esophagus early, since this condition has often been found to be a precursor of esophageal adenocarcinoma. Accordingly, it would be desirable to screen for the condition, even though that would require evaluating the condition of the esophagus in millions of people with chronic heartburn and gastric reflux. However, Barrett's Esophagus and early stage cancers can occur without telltale symptoms, so mass screenings have been proposed as the only viable approach to identify the condition as early as possible to enable treatment and avoid the onset of or provide a curative therapy for the cancerous condition. However, the numbers of people that are likely candidates for esophageal screening and the current cost associated with the practice of flexible endoscopy performed by a physician compared to the reimbursement associated with such mass screenings make this solution currently impractical.
What is needed is a much more efficient and cost effective approach for identifying those people having Barrett's Esophagus. Only a doctor can perform an examination of the esophagus using a conventional flexible endoscope, and the procedure is thus relatively expensive. It would be preferable to develop a different scanning technique that need not be performed by a physician, but instead, can be performed by a trained medical technician or nurse. Indeed, it would also be desirable to automate the evaluation of images produced by imaging the internal surface of the esophagus just proximal of the LES so that the existence of Barrett's Esophagus can be automatically detected either in real time during the scanning operation or immediately thereafter.
To facilitate mass screenings of individuals who may be afflicted with Barrett's Esophagus, it would be desirable to employ a screening device that can readily be introduced into the esophagus, without invoking any gag reflex. Ideally, the scanning device should be embodied in a capsule-shaped housing so that it can simply be swallowed with a glass of water. Accordingly, the device must be sufficiently small in size to enable it to be swallowed by most patients. Further, although such a device might be reusable if properly sterilized, it will likely be preferable to employ a screening device that is sufficiently low in cost as to be disposable after a single use.
An Israeli company, Given Imaging Ltd., has developed a swallowable camera battery-powered capsule that is used in connection with a harness that receives imaging signals transmitted from the capsule. Batteries in the harness are used to provide power for image storage and for a receiver included in the harness that receives a radio signal from a transmitter in the camera capsule. The harness of the camera capsule is worn like a belt while the patient goes about their normal activity during about an eight hour period. The capsule and camera passes through the entire gastrointestinal tract and is expelled with other wastes in a normal fashion. Images taken by the camera and wirelessly transmitted to a receiver on the harness can then be viewed in an attempt to identify various medical conditions in the patient's gastrointestinal tract. The camera-capsule thus provides images of portions of the small intestine that are beyond the reach of a conventional endoscopy using an endoscope, or colonoscope. However, there is no control on the rate at which the camera-capsule moves through the gastrointestinal tract. Also, its position within the gastrointestinal tract is not readily determined. An earlier version of this capsule system has been modified to include a lens on each end of the capsule and to acquire images at a greater frame rate, specifically for imaging the esophagus. This system is still quite expensive and does not enable control of the capsule location by the operator.
Therefore, in addition to providing a scanning device that is useful in scanning the general population for Barrett's Esophagus, it would be desirable to use such a scanning device in many other procedures that require imaging of an interior surface within a body lumen. It would be desirable to control the disposition of the scanning device within the lumen and to enable it to advance based upon muscle tissue action in the wall of the lumen, but to be controlled or even withdrawn back along the path of its travel. Currently, there are scanners that are sufficiently small, but none have yet been provided in a capsule that meets the other desired criteria for imaging internal surfaces within a lumen.